It is known to use a plurality of projection images recorded by an X-ray device in order to reconstruct a three-dimensional image dataset therefrom. This approach is used, for example, in computed tomography scans in which a radiation source and a radiation detector may be rotated about an examination object by a gantry in order to record the object from a plurality of recording angles. Also used, in particular, in the field of medical imaging, are C-arm X-ray devices with which the X-ray detector and the X-ray source are supported by a C-shaped carrier, which may be rotated and/or moved in order to change a recording perspective.
For the provision of X-rays, an X-ray tube may be used as a radiation source. In such cases, it is possible that transient arcing will occur in the X-ray tube thus causing the X-ray tube to be short-circuited for a brief period. During this short circuit, there is a temporary break in the intensity of the X-rays provided. With a two-dimensional X-ray recording, this may result in underexposure of the recording. Where three-dimensional image datasets are to be generated from a plurality of projection images, this arcing is particularly problematic for two reasons. On the one hand, in this case, a plurality of projection images is recorded with relatively short exposure times. This increases the probability of arcing occurring in the context of the data acquisition and the influence of such arcing on the individual projection image is relatively strong. On the other hand, the data from the projection images is combined in the context of the reconstruction of the three-dimensional image dataset. Consequently, the overexposure or underexposure of individual projection images results not in a homogenous change in contrast affecting the whole dataset, but potentially in banding, e.g., contrast variations within the image dataset. These may significantly complicate the interpretation of the image dataset.